2-(Pyrrolidin-1-yl)benzonitrile: Properties & Research Uses
2-(Pyrrolidin-1-yl)benzonitrile: Properties & Research Uses
2-(Pyrrolidin-1-yl)benzonitrile is a versatile aromatic nitrile building block featuring a pyrrolidine donor group ortho to a nitrile acceptor, making it a valuable intermediate in medicinal chemistry and organic synthesis research.
- IUPAC Name
- 2-(Pyrrolidin-1-yl)benzonitrile
- SKU
- B726880
- Molecular Formula
- C₁₁H₁₂N₂
- Molecular Weight
- 172.23 g/mol
- Functional Groups
- Aromatic nitrile (–CN), secondary amine (pyrrolidine ring)
- Compound Class
- Aromatic nitrile / pyrrolidine derivative
- Primary Research Use
- Pharmaceutical intermediate, organic synthesis building block
Chemical Structure and Physicochemical Properties
2-(Pyrrolidin-1-yl)benzonitrile (molecular formula C₁₁H₁₂N₂, MW 172.23 g/mol) consists of a benzonitrile core substituted at the ortho position with a pyrrolidinyl group. This arrangement places a strong π-donor (the tertiary nitrogen of the five-membered pyrrolidine ring) directly adjacent to a π-acceptor (the nitrile group), creating an intramolecular push-pull electronic system across the aromatic ring.
The push-pull character influences several physicochemical properties: the nitrile carbon becomes more electrophilic, while the aromatic ring displays reduced electron density at the ipso and para positions relative to the nitrile. This electronic asymmetry is exploited in downstream synthetic transformations such as nucleophilic aromatic substitution surrogates and cross-coupling reactions. The compound is expected to be a solid or low-melting solid at ambient temperature, with moderate lipophilicity consistent with its mixed polar/nonpolar character.
Note: Specific melting point, boiling point, solubility, and spectroscopic data should be confirmed against the certificate of analysis supplied with SKU B726880.
Synthesis and Preparation Methods
2-(Pyrrolidin-1-yl)benzonitrile is most commonly prepared by nucleophilic aromatic substitution (SNAr) of 2-fluorobenzonitrile or 2-chlorobenzonitrile with pyrrolidine. The nitrile group acts as an ortho activating group, strongly facilitating SNAr by stabilizing the Meisenheimer complex intermediate. This reaction typically proceeds under mild to moderate heating (60–100 °C) in polar aprotic solvents such as DMSO or DMF, often with an inorganic or organic base to neutralize the hydrogen halide generated.
Alternative routes include palladium-catalyzed C–N coupling (Buchwald-Hartwig amination) of 2-halobenzonitriles with pyrrolidine, which is particularly useful when selectivity or functional group tolerance demands it. Both routes are well-established in the pharmaceutical intermediate literature and deliver the target compound in good to excellent yields.
Review flag: Specific reaction conditions (temperature ranges, yields, catalyst loadings) cited here are textbook-level estimates and should be verified against primary literature before use in experimental protocols.
Applications in Medicinal and Organic Chemistry
The compound serves as a versatile building block in medicinal chemistry programs. The nitrile group can be elaborated into amidines, tetrazoles, carboxylic acids, aldehydes, or primary amines via standard functional group interconversions, dramatically expanding the structural diversity accessible from this scaffold. Such transformations are routinely employed in the generation of fragment libraries and lead optimization campaigns.
The ortho-pyrrolidinyl arrangement is also found in pharmacophoric motifs relevant to central nervous system (CNS) drug discovery, where the combination of a lipophilic nitrogen heterocycle and an electron-withdrawing nitrile can fine-tune receptor binding affinity and ADMET properties. Additionally, the push-pull aromatic system makes this compound of interest as a fluorescent probe precursor or in the design of organic dyes exploiting intramolecular charge-transfer (ICT) phenomena.
In synthetic methodology, this compound can act as a substrate for investigating C–H functionalization, electrophilic cyclization, and other modern transformations targeting aromatic systems bearing donor-acceptor substitution patterns.
Handling, Storage, and Safety Considerations
As with all aromatic nitrile compounds, appropriate laboratory safety practices should be followed when handling 2-(Pyrrolidin-1-yl)benzonitrile. Nitrile-containing compounds should be treated with respect, although aromatic nitriles are substantially less acutely toxic than aliphatic nitriles or inorganic cyanides; nonetheless, inhalation of dust or prolonged skin contact should be avoided. Use of appropriate personal protective equipment (PPE) — including nitrile gloves, safety glasses, and a laboratory coat — is recommended. Work in a well-ventilated fume hood when weighing or dissolving the compound.
The compound should be stored in a cool, dry location away from strong oxidizing agents, strong acids, and strong bases. Sealed containers under an inert atmosphere are advisable if long-term storage stability is required. Always consult the Safety Data Sheet (SDS) supplied with SKU B726880 for authoritative hazard classifications, first-aid measures, and disposal guidance compliant with local regulations.
Review flag: GHS hazard classification, specific H/P statements, and flash point data must be confirmed from the official SDS for B726880.
Frequently asked questions
What is 2-(Pyrrolidin-1-yl)benzonitrile used for in research?
It is primarily used as a pharmaceutical intermediate and organic synthesis building block. The nitrile group can be converted into a range of functional groups, and the push-pull aromatic scaffold is relevant to CNS drug discovery, fluorescent probe development, and methodology studies involving donor-acceptor aromatic systems.
How is 2-(Pyrrolidin-1-yl)benzonitrile typically synthesized?
The most common route is nucleophilic aromatic substitution (SNAr) of 2-fluorobenzonitrile or 2-chlorobenzonitrile with pyrrolidine, facilitated by the ortho-nitrile activating group. Palladium-catalyzed Buchwald-Hartwig C–N coupling of 2-halobenzonitriles with pyrrolidine is also applicable when greater functional group tolerance is needed.
What are the recommended storage conditions for SKU B726880?
The compound should be stored in a cool, dry place away from strong oxidizing agents, acids, and bases, in a sealed container. For long-term storage, an inert atmosphere is advisable. Please refer to the official SDS and certificate of analysis for definitive storage temperature and condition specifications.
What solvents are suitable for dissolving 2-(Pyrrolidin-1-yl)benzonitrile?
Based on its mixed polar and nonpolar character, common polar aprotic solvents such as DMSO, DMF, and acetonitrile, as well as chlorinated solvents like dichloromethane, are expected to be suitable. Solubility in aqueous systems will be limited. Actual solubility data should be confirmed experimentally or from the product SDS.
Is 2-(Pyrrolidin-1-yl)benzonitrile hazardous?
Aromatic nitriles are generally of lower acute toxicity than aliphatic nitriles, but standard laboratory precautions apply: wear appropriate PPE including nitrile gloves and eye protection, avoid inhalation of dust, and work in a ventilated fume hood. Always consult the official SDS for B726880 for complete and authoritative hazard information.
References
- March, J. Advanced Organic Chemistry: Reactions, Mechanisms, and Structure, 4th ed.; Wiley-Interscience: New York, 1992. (Nucleophilic Aromatic Substitution, Chapter 13)
- Hartwig, J. F. Carbon-Heteroatom Bond-Forming Reductive Eliminations of Amines, Ethers, and Sulfides. Acc. Chem. Res. 1998, 31, 852–860. doi:10.1021/ar970282g
- Clayden, J.; Greeves, N.; Warren, S. Organic Chemistry, 2nd ed.; Oxford University Press: Oxford, 2012. (Nitrile chemistry and functional group interconversions)
Products are supplied for research and development use only. Not for use in humans, animals, diagnosis, or therapy.
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